1. Field of the Invention
The present invention relates to a communication device for use in the field of telemetering including collection of information on selling with vending machines, in the field of telematics including distribution of traffic information to mobile units, and in other fields.
2. Description of the Related Art
In recent years, telemetering and telematics including collection/distribution of information via a wireless packet communication network have come into wide use. Telemetering was originally a generic name for systems for reading out measured values from measuring instruments by using a communication line. In recent years, however, it has been generally used as a term not only for data reading but also for operation monitoring and remote control of appliances. Typical examples of telemetering are a system for management of selling with vending machines, a system for management of the amount of use of gas or city water and a system for management in unmanned parking lots. See Japanese Patent Publication No. 2003-51056 about a conventional vending machine selling management system. Telematics means real-time provision of information service using a combination of a mobile unit such as a motor vehicle and a communication system. A Typical example of telematics is a vehicle information system for providing traffic information and navigation information in real time to a terminal provided on a motor vehicle.
In such a field, data circuit-terminating equipment (DCE) for connection to a wireless packet communication network in a remote place and data terminal equipment (DTE) using the data circuit-terminating equipment are disposed. For example, in a vending machine selling management system, a controller for performing selling control and control of the temperature in a chamber corresponds to data terminal equipment. The data terminal equipment connects to a predetermined network periodically or at arbitrary times via data circuit-terminating equipment to connect to a predetermined management computer via the network. The data terminal equipment connected to the management computer transmits various sorts of control object data.
In such a field, a management computer manages data terminal equipment. However, main items of data to be handled for management are data on various operations in appliances under management. In some cases, management of data terminal equipment is not adequately performed with respect to circumstances under which the data terminal equipment is installed. Even in a case where management involved with circumstances under which data terminal equipment is installed is performed in the management computer, it is difficult to accurately maintain management data on the circumstances. For example, a service worker or the like in a store where data terminal equipment is installed may change the placement of the data terminal equipment without permission or may replace the data terminal equipment with a spare one. In such a situation, there is a possibility of change information being not reflected in management data. In some cases, therefore, there is a possibility of data terminal equipment not being installed in a place designated by management data when a system manager goes to the designated place for a maintenance/operation purpose. This is a hindrance to maintenance and service.